Table 4.

Summary showing which studies reported significant and non-significant associations between carotid disease and retinopathy

Carotid disease variable		Any diabetic retinopathy	Other diabetic retinopathy
CCA IMT	Non-significant	Alonso [28] Cardoso [29] Distiller [31] Yun [10] Araszkiewicz [30]	Alonso [28]—DR severity Cardoso [23]— new or worsening DR
	Significant	Liu [34] Jung [27]	Ichinohasama [8]—mild NPDR
Other IMT	Non-significant	Alonso [28]—BIF Cardoso [29]—ICA & BIF	Alonso [28]—ICA & BIF, DR severity Cardoso [23] —ICA & BIF, new or worsening DR
	Significant	Alonso [28]—ICA Rema [9]—Mean IMT
Plaque/Stenosis	Non-significant	Hjelmgren [32] Carbonell [7] Jung [27] Yun [10]	Alonso [28]—DR severity Cardoso [23]—new or worsening DR
	Significant	Liu [34] Alonso [28] Lacroix [33] Distiller [31] Cardoso [29]	Carbonell [7]—advanced DR
Other	Non-significant	Distiller [31]—IMT risk
	Significant	Liu [34]—any plaque and/or CCA IMT > 1 mm Son [10]—any plaque and/or CCA IMT > 0.9 mm

BIF bifurcation, CCA common carotid artery, DR diabetic retinopathy, ICA internal carotid artery, IMT intima-media thickness